Blockchain-based currencies use encoded strings, which are a Base58Check encoding of some hash, typically that of a public key. The encoding includes a prefix (traditionally a single version byte), which affects the leading symbol(s) in the encoded result. The following is a list of some prefixes which are in use in the reference Bitcoin codebase.[1][2]

Note that private keys for compressed and uncompressed bitcoin public keys use the same version byte. The reason for the compressed form starting with a different character is because a 0x01 byte is appended to the private key before base58 encoding.

The following table shows the leading symbol(s) and address length(s) for 160 bit hashes for each of the possible decimal version values: